SleepWell Blog

Why I Dopamine Fast as a Silicon Valley Chemist


Hi, I’m James Sinka, the co-founder and CEO of, a Y Combinator W19 company. I’m a chemist, functional biohacker, and dopamine faster. I chose to write about my experience after the positive replies I received when Janey Muñoz’s (YCW19) tweet went viral.



TL;DR: Like drugs, natural and behavioral rewards can induce addictive behavior. Life as an addict is difficult, so twice a year I dopamine fast where I deliberately avoid behavioral, environmental, and biochemical stimulus that might be addictive. The benefits of fasting these stimuli include improved concentration and more sustained flow. Dopamine fasting gives me the vital clarity to separate signal from noise so I can accomplish what I want out of life, especially in our modern, overstimulated world.


Here’s a short on how dopamine fasting feels.

After a Dopamine Fast, I feel reset — emotionally, physically, and mentally. I have improved concentration and have an easier time getting into flow, where concentration is effortless. I am laser-focused on my task at hand. A dopamine fast makes work more exciting, more stimulating, and easier to accomplish. Total productivity hack. Those who are working 60 or more hours a week could potentially see a massive boost in their productivity from a dopamine fast, especially those who need to spend large amounts of time executing.

Added bonuses from dopamine fasting include more rewarding meals, more enjoyment while exercising, an increase in overall energy, and deeper immersion, connection, and empathy with others.

When I do a proper dopamine fast, I completely cut out three classes of stimuli (behavioral, environmental, and biochemical) for 24 hours. This includes [Behavioral] work, exercise, chores of any kind, then [Environmental] conversing, reading, TV, phone calls, texting, music, and [Biochemical] calories, drugs, alcohol, and stimulants such as coffee and tea). I avoid all of these activities because natural and behavioral rewards/stimuli can induce addictive behavior.

Natural and behavioral rewards/stimuli can induce addictive behavior.

Instead, I’ll allow myself to sit quietly, meditate, reflect, journal, think, walk, shower, nap, take in the sun and gaze at the sky.

When I’m not constantly bombarded by stimuli (internet, work, music, etc.) I can see the bigger picture again. It’s refreshing.

Dopamine fasting is a synthesis of experiments I’ve done in my life, using scientific logic, so I adopt the term ‘dopamine fasting’ for continuity of discussion.


Food Fasting

My first food fast was unintentional — in high school, I got sick and was unable to eat. After recovering the first thing I ate was a plump, farm-fresh peach. It was deliciously intense in the moment. I found Nirvana. Do you remember the first time you had guacamole? It was likely super memorable!

And why was that? Dopamine! This guacamole stimulus leads to a natural and pleasurable (opioid triggering) reward of delicious guacamole, so the brain rewards you with dopamine, to reinforce learning.

The more you eat guacamole, the more familiar and less novel it becomes. While eating guacamole every day sounds great, the reality is that eating only guacamole gets quite boring and less stimulating. Just like drug use. Similar to drugs, abstinence decreases the pleasure threshold, or in the case of guacamole, guacamole abstinence, makes guacamole amazing again. A food fast increases the reward and pleasure of food.

There’s loads of science detailing the benefits of food restriction, including weight and blood pressure management, improved mitochondrial (ATP) efficiency, and as a cancer deterrent. Unbelievable, right?! So I began to fast monthly at 20. To this day, my close friends and I food fast monthly and do intermittent fasting + keto daily.


Internet fasting

Back in high school, I, like others, fell prey to internet addiction by playing World of Warcraft (WoW). My responsibilities forced me to start a WoW fast and I was shocked much more fun WoW was when limited. After reading various papers and studying the addictive neurobiological mechanisms of drugs, it became obvious. I was physically addicted to WoW.

This internet addiction struck once more via social media use (Twitter, Facebook, Instagram, Snapchat) and even texting. Stuck again. I found myself craving a notification and would be depleted when I didn’t receive one. I could feel I’d been trained like Pavlov’s dogs; excited and ready at the ring of my notification bell. (Ding!)

Then I read Hooked by Nir Eyal. He details how companies like Facebook intentionally engineer drug mimicking stimulation into their apps. (Ding!) One of the most effective cures for addiction is abstinence — so I completed a few electronics fasts and they helped. (No ding…) It required force of will, but abstinence was super effective at undoing the trained behavior of jumping out of my seat at the ring of the bell. (No ding…)

I extrapolated the drug response mechanism to broader aspects of life, later learning ΔFosB was to blame. ΔFosB, a protein produced from the human genome, triggers natural rewards under normal conditions, during pathological addictive-like states, and during exposure to addictive drugs. Therefore: Natural & behavioral rewards can induce addiction, like drugs.


Are we permanently fucked?

Now that science has proved that the internet, food and more can be just as addictive as drugs (thanks ΔFosB), what can we do?

We abstain from stimulus. We let go and find clarity. We sit quietly, meditate, reflect, journal, think, walk, shower, nap, take in the sun & gaze at the sky.

Minimize stimuli. Reconnect with yourself. Take in the real world.


Why now?

Stimulating activity stifles deep thinking. No matter the stimulus, whether it’s food, the internet, drugs, or something else, the brain is occupied consuming it. This disables deep thought. It holds back our potential. We can undo this by doing a distraction fast. Yes, some people would benefit greatly from just an electronics fast, but a full dopamine fast gives you the most leverage. By cutting all stimuli we are forced to reflect and think deeper.

The brain gets used to stimuli, just like when you ignore a bad smell that’s been around long enough. Tolerance increases, making certain tasks unable to compete with the attention-grabbing dopamine release that of the new, elevated, normal. Dopamine tolerance means that more dopamine is now needed for you to complete a task at hand. Subsequently, that means even more effort and focus is required to complete important tasks. Hard work gets harder. Frequent bursts of dopamine add friction to life. Who needs that? Normal activities like email or exercise provide less dopamine, vs Instagram or dessert, making email or exercise harder to get done. Dopamine overstimulation makes life harder. Get off the dopamine treadmill.


How does dopamine fasting add leverage?

Dopamine fasting transformed weeks of analytical chemical drudgery into excitement and anticipation. In hindsight, my experiments were the most interesting thing I allowed myself to do. I was obsessed! This newfound focus enabled me to outwork PhDs, as an undergrad and led me to win a renewable energy research grant from the State of New York.

I’ve completed two dopamine fasts in 2019. My first was after moving to San Francisco for Y Combinator W19 and again after YC’s demo day. I experienced full “go-go-go” sprint mode for 10 weeks, then transitioned to fundraising to fuel our company. All that activity was insanely stimulating. Later, I used dopamine fasting to shed the expectations associated with a super stimulating lifestyle, and returned to the steady grind of building a company.

OK, James is crazy. Why should I try this?

Dopamine fasting is the ultimate productivity hack! It makes work more exciting, stimulating, and easier to accomplish. Anyone who is working on creative endeavors (engineers, artists, designers, writers, etc) can benefit from reconnecting with their creative side through a dopamine fast. There’s so much to gain. It is especially critical for entrepreneurs because, as founders, our output is strongly tied to our worth.

Dopamine fasting additionally maximizes the value of meditation to reduce stress and improve quality of life. It silences the instant gratification monkey inside. Peace, at last.

A dopamine fast is the perfect time to look at your life and its trajectory. To reflect on what makes you grateful to be alive, examine your trajectory, and connect with your subconscious. To plan & reflect. Post-dopamine fast, you’re fresh, restored, untethered. So get after it! Start the project or habit, and get back in control.

No other life hacks, biohacks, or even drugs (yes, that means you too, caffeine) have had more of an impact on my life and productivity; other than Sleep.


Final thoughts on optimization

While I dopamine fast twice a year, I focus on sleep optimization daily. Biochemically, we need oxygen to breathe, water to hydrate, and sleep to renew. Humans survive over a month without food or exercise, but without sleep, you soon perish.

One night of sleep loss impairs innovative thinking & flexible decision making. Bad sleep can even increase your likelihood of dying. I’ve witnessed the critical importance of sleep, which led me to found to optimize and maximize sleep quality, using data & peer-reviewed science.


Dopamine Fasting

The above is a synthesis of my personal experience and peer-reviewed science. This is NOT medical advice. I will use medication as prescribed and talk to my doctor, as you should.

I would, however, suggest researching dopamine fasts to anyone who has lost touch with the big picture, who feels like there are a trillion things to do but there’s no time, who doesn’t feel rested after a break.

Unhook the Ding!

Connect with life.

Wield the science of How and Why to learn what works for you.

Your next dopamine fast is worth the vacation day.


Thanks to everyone who reviewed a draft of this, including; Pranay, Alberto, Andrew, Tunde, Annika, Erin, Nathaniel, Peer, Julia, Richard, Courtney, and Lindsay


Written by: James Sinka

Good Sleep > Dopamine Fasting

Find out if SleepWell is right for you!

Request Access